Massage chair

ABSTRACT

A massage chair includes: a base unit; a rocker mechanism including an actuator that is coupled to the base unit, at least one output bar that is connected pivotally to the base unit, an input bar that is connected to and that is driven rotatably by the actuator, and a connecting bar that is connected pivotally to the input bar and the output bar; and a seat unit connected immovably to the output bar. The input bar, the output bar, the connecting bar, and the base unit cooperate to constitute a crank-rocker planar four-bar linkage. The actuator actuates rotation of the input bar, which in turn drives reciprocating swing motion of the output bar and the seat unit.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a massage apparatus, more particularly to amassage chair.

2. Description of the Related Art

A conventional massage apparatus, such as a vibrating chair, generallyvibrates to massage a user's body. However, the vibrating chair usuallyvibrates only in a vertical direction such that the massage effect maybe insufficient if the vibrating chair vibrates in a low frequency, andthat the user may feel uncomfortable if the vibrating chair vibrates ina high frequency.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide a massagechair that is effective and comfortable to use.

Accordingly, a massage chair of the present invention comprises:

a base unit;

a rocker mechanism including

-   -   an actuator that is coupled to the base unit,    -   at least one output bar that is connected pivotally to the base        unit,    -   an input bar that is connected to and that is driven rotatably        by the actuator, and    -   a connecting bar that has opposite ends connected pivotally and        respectively to the input bar and the output bar, and that        cooperates with the input bar, the output bar, and the base unit        to constitute a crank-rocker planar four-bar linkage; and

a seat unit connected immovably to the output bar;

wherein the actuator actuates rotation of the input bar, which in turndrives reciprocating swing motion of the output bar and the seat unit.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will becomeapparent in the following detailed description of the preferredembodiment with reference to the accompanying drawings, of which:

FIG. 1 is an assembled perspective view of a preferred embodiment of amassage chair according to the invention;

FIG. 2 is a partly exploded perspective view of the preferredembodiment;

FIG. 3 is a side view of the preferred embodiment between an utmostrearward inclined position and an utmost forward inclined position;

FIG. 4 is another side view of the preferred embodiment at the utmostrearward inclined position; and

FIG. 5 is another side view of the preferred embodiment at the utmostforward inclined position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIGS. 1 to 3, a preferred embodiment of a massage chairaccording to the present invention comprises a base unit 2, a rockermechanism 3 and a seat unit 4.

The base unit 2 includes a plurality of spaced-apart foot members 21,and a bracket 22 having a horizontal plate portion that bridges the footmembers 21 and a vertical plate portion that extends upwardly from alateral end of the horizontal plate portion and that has a plurality ofoblong slots 221.

The rocker mechanism 3 includes an actuator 31, a pivot shaft 23, a pairof spaced-apart output bars 32, 35, an input bar 33, and a connectingbar 34.

The actuator 31 is a driving motor, and has an actuator shaft 311extending substantially horizontally through the vertical plate portionof the bracket 22 of the base unit 2. The input bar 33 has one endconnected perpendicularly and co-rotatably to the actuator shaft 311.The pivot shaft 23 is mounted to the vertical plate portion of thebracket 22 substantially horizontally, is lower than the actuator shaft311, and extends through lower ends of the output bars 32, 35 to connectpivotally the lower ends of the output bars 32, 35 to the bracket 22.The actuator shaft 311 is disposed more forward than the pivot shaft 23so that an imaginary surface interconnecting the actuator shaft 311 andthe pivot shaft 23 inclines forward with respect to a vertical surfacepassing through the pivot shaft 23. The connecting bar 34 has one endconnected pivotally to another end of the input bar 33 opposite to theactuator shaft 311, and the other end connected pivotally to an upperportion of the output bar 32.

The rocker mechanism 3 further includes a frame member 36 bridging andconnecting immovably the upper portion of the output bar 32 and an upperportion of the output bar 35 above the connecting bar 34, and a pair ofreinforcing links 37, each of which has a bottom end connected immovablyto the lower end of a respective one of the output bars 32, 35, and atop end connected immovably to the frame member 36 and spaced apart fromthe upper portion of the respective one of the output bars 32, 35. Therocker mechanism 3 further includes a plurality of fasteners extendingrespectively through the oblong slots 221 and fastening the actuator 31to the bracket 22. The actuator 31 is adjustable in position when thefasteners are unfastened and moved along the oblong slots 221.

The seat unit 4 includes a seat member 41 connected immovably to theframe member 36 of the rocker mechanism 3, and a backrest member 42connected to the seat member 41.

The input bar 33, the output bar 32, the connecting bar 34 and thebracket 22 constitute a planar four-bar linkage. In this embodiment, thelengths of segments of the input bar 33, the output bar 32, the bracket22 and the connecting bar 34 between intersections in this four-barlinkage can be denoted by a, b, g and h respectively (see FIG. 3), andthe relations between the lengths are specified as follows: b+g>a+h,b+h>a+g, and g+h>a+b. As such, this four-bar linkage is configured as acrank-rocker four-bar linkage, and the output bars 32, 35 (also the seatunit 4) swing between an utmost rearward inclined position (see FIG. 4)and an utmost forward inclined position (see FIG. 5).

The input bar 33 is driven rotatably by the actuator 31 to drivereciprocating swing motion of the output bars 32, 35 and the seat unit 4between the utmost rearward inclined position and the utmost forwardinclined position via the connecting bar 34. The output bars 32, 35 forma greatest forward tilted angle with respect to the vertical surfacepassing through the pivot shaft 23 when being tilted forward, and form agreatest rearward tilted angle with respect to the vertical surfacepassing through the pivot shaft 23. The rearward tilted angle is largerthan the forward tilted angle.

Referring to FIGS. 4 and 5, when the input bar 33 rotates clockwise in aconstant rotational speed, a rotational movement that the input bar 33rotates from the utmost rearward inclined position to the utmost forwardinclined position is larger than that from the utmost forward inclinedposition to the utmost rearward inclined position, so that the forwardinclining speed of this embodiment is smaller than the rearwardinclining speed.

To sum up, the massage chair of this invention has the followingadvantages:

1. Compared to the conventional massage chair illustrated in the priorart which has only a vertical vibration, the swing motion of thismassage chair with different forward and rearward inclining speeds hasan enhanced effect of exercise to the user's body, and makes the massagecomfortable to use.

2. The reinforcing links 37 strengthen the whole structure of thismassage chair, thereby resulting in a relatively long service life.

3. Since the actuator 31 is adjustable in position along the oblongslots 221, the range of the swing motion of this massage chair can bechanged for suiting different users.

It is noted that the seat unit 4 maybe provided with handles or a seatbelt to guarantee the safety of the user.

While the present invention has been described in connection with whatis considered the most practical and preferred embodiment, it isunderstood that this invention is not limited to the disclosedembodiment but is intended to cover various arrangements included withinthe spirit and scope of the broadest interpretation so as to encompassall such modifications and equivalent arrangements.

What is claimed is:
 1. A massage chair comprising: a base unit; a rockermechanism including an actuator that is coupled to said base unit, atleast one output bar that is connected pivotally to said base unit, aninput bar that is connected to and that is driven rotatably by saidactuator, and a connecting bar that has opposite ends connectedpivotally and respectively to said input bar and said output bar, andthat cooperates with said input bar, said output bar, and said base unitto constitute a crank-rocker planar four-bar linkage; and a seat unitconnected immovably to said output bar; wherein said actuator actuatesrotation of said input bar, which in turn drives reciprocating swingmotion of said output bar and said seat unit.
 2. The massage chair asclaimed in claim 1, wherein said rocker mechanism includes a pair ofsaid output bars, and further includes a frame member bridging andconnecting immovably said output bars.
 3. The massage chair as claimedin claim 2, wherein said seat unit includes a seat member fixed to saidframe member of said rocker mechanism, and a backrest member connectedto said seat member.
 4. The massage chair as claimed in claim 3, whereinsaid rocker mechanism further includes a pair of reinforcing links, eachof which is connected between said frame member and a respective one ofsaid output bars.
 5. The massage chair as claimed in claim 4, whereinsaid base unit includes a plurality of spaced-apart foot members, and abracket bridging said foot members, said actuator being connected tosaid bracket.
 6. The massage chair as claimed in claim 5, wherein saidbracket of said base unit has an oblong slot, and a fastener extendingthrough said oblong slot and fastening said actuator to said bracket,said actuator being adjustable in position when said fastener isunfastened and moved along said oblong slot.
 7. The massage chair asclaimed in claim 1, wherein said actuator is a driving motor.
 8. Themassage chair as claimed in claim 1, wherein said actuator has anactuator shaft extending substantially horizontally and connected tosaid input bar, and said rocker mechanism further includes a pivot shaftthat is mounted to said base unit substantially horizontally, that islower than said actuator shaft, and that extends through a lower end ofsaid output shaft to connect pivotally said lower end to said base unit.9. The massage chair as claimed in claim 8, wherein said input bar hasone end connected to said actuator shaft, said connecting bar having oneend connected pivotally to another end of said input bar and having theother end connected pivotally to an upper portion of said output bar,said seat unit being connected immovably to said upper portion of saidoutput bar and being disposed above said connecting bar.
 10. The massagechair as claimed in claim 9, wherein said actuator shaft is disposedmore forward than said pivot shaft so that an imaginary surfaceinterconnecting said actuator shaft and said pivot shaft inclinesforward with respect to a vertical surface passing through said pivotshaft.
 11. The massage chair as claimed in claim 10, wherein said outputbar, when being tilted forward, forms a greatest forward tilted anglewith respect to the vertical surface passing through said pivot shaft,and said output bar, when being tilted rearward, forms a greatestrearward tilted angle with respect to the vertical surface passingthrough said pivot shaft, the rearward tilted angle being larger thanthe forward tilted angle.
 12. The massage chair as claimed in claim 9,wherein said rocker mechanism includes a pair of said output bars, andfurther includes a frame member bridging said upper portions of saidoutput bars and fixed below said seat unit, and a pair of spaced-apartreinforcing links, each of said reinforcing links having a bottom endconnected immovably to said lower end of a respective one of said outputbars, and a top end connected immovably to said frame member and spacedapart from said upper portions of said output bars.
 13. The massagechair as claimed in claim 9, wherein said base unit includes a pluralityof spaced-apart foot members, and a bracket bridging said foot membersand extending upwardly, said pivot shaft and said actuator being mountedto said bracket.